SN4 ""

No	Pattern	Freq
1	have [been] used [adv] for	12
2	have [been] used [adv] for	12
3	[noun] have [been] used for	82
4	[pron] have [been] used for	42
5	[noun sg] have [been] used for	38
6	[noun pl] have [been] used for	37
7	which have [been] used for	22
8	[Wh det] have [been] used for	22
9	which have [been] used for	22
10	[conj] have [been] used for	20
11	[pers pn] have [been] used for	19
12	[vb mod] have [been] used for	15
13	[modal v] have [been] used for	15
14	it have [been] used for	14
15	that have [been] used for	14
16	that have [been] used for	14
17	it have [been] used for	14
18	[that] have [been] used for	14
19	[verb] have [been] used for	9
20	[adv] have [been] used for	8
21	[adj] have [been] used for	8
22	[adv] have [been] used for	7
23	[vb pp] have [been] used for	6
24	could have [been] used for	6
25	could have [been] used for	6
26	[noun prp] have [been] used for	5
27	may have [been] used for	5
28	[coord] have [been] used for	5
29	may have [been] used for	5
30	have [adv] [been] used for	43